DocumentCode :
3117663
Title :
The DoF of the K-user interference channel with a cognitive relay
Author :
Chaaban, Anas ; Sezgin, Aydin
Author_Institution :
Dept. of Commun. Syst., Ruhr-Univ. Bochum, Bochum, Germany
fYear :
2012
fDate :
1-6 July 2012
Firstpage :
1503
Lastpage :
1507
Abstract :
It was shown recently that the 2-user interference channel with a cognitive relay (IC-CR) has full degrees of freedom (DoF) almost surely, that is, 2 DoF. The purpose of this work is to check whether the DoF of the K-user IC-CR, consisting of K user pairs and a cognitive relay, follow as a straight forward extension of the 2-user case. As it turns out, this is not the case. The k-user IC-CR is shown to have 2K/3 DoF if K >; 2 for the when the channel is time varying, achievable using interference alignment. Thus, while the basic k-user IC with time varying channel coefficients has 1/2 DoF per user for all K, the k-user IC-CR with varying channels has 1 DoF per user if K = 2 and 2/3 DoF per user if K >; 2. Furthermore, the DoF region of the 3-user IC-CR with constant channels is characterized using interference neutralization, and a new upper bound on the sum-capacity of the 2-user IC-CR is given.
Keywords :
cognitive radio; radiofrequency interference; time-varying channels; cognitive relay; constant channels; degrees of freedom; interference alignment; k-user IC-CR; k-user interference channel; time varying channel coefficients; two-user interference channel; upper bound; Integrated circuits; Interference channels; Receivers; Relays; Upper bound; Vectors;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Information Theory Proceedings (ISIT), 2012 IEEE International Symposium on
Conference_Location :
Cambridge, MA
ISSN :
2157-8095
Print_ISBN :
978-1-4673-2580-6
Electronic_ISBN :
2157-8095
Type :
conf
DOI :
10.1109/ISIT.2012.6283514
Filename :
6283514
Link To Document :
بازگشت